Tissue engineered meat for consumption and a method for producing tissue engineered meat for consumption

ABSTRACT

A non-human tissue engineered meat product and a method for producing such meat product are disclosed. The meat product comprises muscle cells that are grown ex vivo and is used for food consumption. The muscle cells may be grown and attached to a support structure and may be derived from any non-human cells. The meat product may also comprise other cells such as fat cells or cartilage cells, or both, that are grown ex vivo together with the muscle cells.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.09/991,544, filed Nov. 16, 2001, which claims priority to U.S.Provisional Patent Application No. 60/60/249,993, filed Nov. 17, 2000,both of which are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The field of the present invention relates to producing and harvestingmeat products for consumption. In particular, it relates to tissueengineered meat for consumption.

BACKGROUND OF THE INVENTION

Meat products such as beef, pork, lamb, poultry, or fish are desirableproducts for food consumption. Meat products are currently produced fromwhole animals, which is a highly inefficient production method because asignificant portion of all agriculturally produced grain is used foranimal rather than human consumption. In the United States, for example,livestock feed accounts for approximately 70% of all the wheat, corn,and other grain produced. In addition, to produce one pound of beef,thousands of pounds of water are required for the animal to drink and togrow the livestock feed. Meanwhile, throughout the world, by someaccount, over 800 million people are malnourished and 50,000 people dieof starvation every day.

Current meat production methods are also harmful to the environment.Rain forests are depleted at a rate of approximately 500 square feet ofrain forest for every pound of beef to be grown. Likewise, moderntechniques for fishing marine life have become so efficient that theoceans and lakes are over-fished. Species that were once common are nowendangered or extinct.

Current scientific efforts to address these problems have focused onincreasing the effectiveness of breeding or growing livestock. Forexample, growth hormones have been used to make livestock grow fasterand thus, consume less grain and water. Growth hormones are typicallyinjected into the livestock, but new methods of introducing the growthhormone have also been developed using genetic engineering technologiessuch as transgenics or cloning of the whole animal. Current meatproduction methods, nonetheless, require water, grain, and land to raiselivestock.

Another problem with current meat production methods involves foodcontamination. Every year, on average, each American becomes sick and9,000 people die from something they have injested. To control foodcontamination, the government's present strategy is to inspect meatduring processing. The USDA and the FDA, however, rarely regulate thefarms where pathogens originate because they lack the regulatory powersover the farms. Nonetheless, except for E. coli 0156:H7, dangerousbacteria are legally considered “inherent” to raw meat. Two of the“inherent bacteria,” however,—campylobacter and salmonella—account for80% of all illnesses and 75% of all deaths from meat and poultryconsumption.

In the poultry industry, for example, as much as 25% of broiler chickensand 45% of ground chickens are reportedly allowed to test positive forsalmonella. The Center for Disease Control estimates that campylobacterinfects 70% to 90% of all chickens. Campylobacter infections causecramps, bloody diarrhea, and fever. Every year in the United States,campylobacter infection results in about 800 deaths. Infections withcampylobacter may also lead to Guillian-Barre syndrome, a disease thatrequires intensive care for several weeks. The incidence of seriousillness and death from these bacteria may increase as moreantibiotic-resistant strains develop. This has caused some scientists toquestion the continued use of antibiotics as a feed supplement forlivestock.

Thus, there exists a need to produce meat products for consumption thatis more efficient, safer, and healthier than the current methods ofproduction.

SUMMARY OF THE INVENTION

The present invention is directed to tissue engineered meat products andmethods for producing such meat products. In one embodiment of theinvention, the meat product comprises muscle cells that are grown exvivo. These muscle cells may be grown and attached to a supportstructure and may be derived from any non-human cells. In a preferredembodiment of the invention, the meat product is substantially free fromany harmful microbial or parasitic contamination. Another embodiment ofthe invention is directed to a meat product comprising muscle cells andother cells such as fat cells or cartilage cells, or both, that aregrown ex vivo together with the muscle cells. In another embodiment ofthe invention, the meat product comprises muscle cells that have beenexposed to an electric or oscillating current.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT

Generally, meat products are taken from the muscles of animals. Butcherscarve out corresponding cuts of beef, poultry, lamb, fish, or pork to besold as steak, chicken breast, lamb chops, fish fillet, pork chops, etc.Meat products also include meat-product derivatives such as ground meatthat may be processed into meatball, hamburger patty, fishball, sausage,salami, bologna, ham, etc. Meat products may also include muscle tissuesor meat that has been seasoned or dried such as jerky.

One embodiment of the present invention involves a method for producingmeat products that may be used for consumption. The method may includeculturing muscle stem cells in vitro and allowing these cells todifferentiate into specific types of muscle cells such as skeletalmuscle cells or smooth muscle cells ex vivo. Muscle cells may be derivedfrom any non-human animals consumed by humans such as mammals (e.g.cattle, buffalo, pigs, sheep, deer, etc.), birds (e.g. chicken, ducks,ostrich, turkey, pheasant, etc.), fish (e.g. swordfish, salmon, tuna,sea bass, trout, catfish, etc.), invertebrates (e.g. lobster, crab,shrimp, clams, oysters, mussels, sea urchin, etc.), reptiles (e.g.snake, alligator, turtle, etc.), and amphibians (e.g. frog legs).Preferably, muscle cells are derived from pluri-potent embryonicmesenchymal stem cells that give rise to muscle cells, fat cells, bonecells, and cartilage cells. The muscle cells may also be derived fromtoti-potent embryonic stem cells such as cells from the blastocyststage, fertilized eggs, placenta, or umbilical cords of these animals.

Muscle cells may be grown in culture into muscle tissues that areattached to a support structure such as a two or three-dimensionalscaffold or support structure. The muscle cells may be grown on the twodimensional support structure such as a petri-dish forming severallayers of cells that may be peeled and processed for consumption. Otherexamples of two dimensional support structures may include porousmembranes that allow for diffusion of nutrients from culture media onone side of the membrane to the other side where the cells are attached.In this type of culture conditions, additional layers of cells may beachieved by exposing the cells to culture media from both sides of themembrane, i.e., cells received nutrients through diffusion from one sideof the membrane and also from the culture media covering the cellsgrowing on the membrane.

Muscle cells may also be grown on, around, or inside a three-dimensionalsupport structure. The support structure may be sculpted into differentsizes, shapes, and forms, as desired, to provide the shape and form forthe muscle cells to grow and resemble different types of muscle tissuessuch as steak, tenderloin, shank, chicken breast, drumstick, lamb chops,fish fillet, lobster tail, etc. The support structure may be made fromnatural or synthetic biomaterials that are preferably non-toxic so thatthey may not be harmful if ingested. Natural biomaterials may include,for example, collagen, fibronectin, laminin, or other extracellularmatrices. Synthetic biomaterials may include, for example,hydroxyapatite, alginate, polyglycolic acid, polylactic acid, or theircopolymers. The support structure may be formed as a solid or semisolidsupport.

To provide for optimal cell and tissue growth, the support structure,preferably, has high porosity to provide maximal surface area for cellattachment. A three-dimensional support structure may also be molded toinclude a branched vascular network providing for delivery of nutrientsinto and shuttling out of metabolites from the cells at the inner massof the meat product. In this particular embodiment, the branch vascularnetwork may be edible by using non-toxic natural or syntheticbiomaterials as mentioned above. Furthermore, the support structure mayalso include adhesion peptides, cell adhesion molecules, or other growthfactors covalently or non-covalently associated with the supportstructure. Examples of the peptides include sequences such asArg-Gly-Asp or Arg-Glu-Asp-Val. Niklason, L., et. al., Advances inTissue Engineering of Blood Vessels and Other Tissues, TransplantImmunology, 5(4):303-306 (1997). This reference is hereby incorporatedby reference as if fully set forth herein.

On the other hand, culture conditions for these muscle cells may includestatic, stirred, or dynamic flow conditions. For scaled up production,the preferred method is to use a bioreactor, which produces greatervolume of cells and allows greater control over the flow of nutrients,gases, metabolites, and regulatory molecules. Furthermore, bioreactorsmay provide physical and mechanical signals such as compression tostimulate cells to produce specific biomolecules. Vacanti, J., et. al.,Tissue Engineering: The Design and Fabrication of Living ReplacementDevices for Surgical Reconstruction and Transplantation, Lancet, 354Suppl. 1, pSI32-34 (1999). This reference is hereby incorporated byreference as if fully set forth herein.

In another embodiment of the invention, meat products derived frommuscle cells grown ex vivo may include fat cells derived also from anynon-human animals. Fattier meat is generally tastier, but with greaterfat content comes greater risk of adverse health consequences such asheart disease. Thus, the ratio of muscle cells to fat cells may beregulated in vitro to produce the meat products with optimal flavor andhealth effects. Regulation may be achieved by controlling the ratio ofmuscle and fat cells that are initially seeded in culture and/or byvarying, as desired, the concentrations and ratio of growth factors ordifferentiation factors that act upon the muscle cells or fat cells.

In another embodiment of the invention, cartilage derived fromchondrocytes may first form an underlying support layer or structuretogether with the support structure. Afterwards, muscle cells or fatcells, or both, may be seeded onto the chondrocyte layer. Theinteraction of muscle cells and chondrocytes may further provide thenecessary regulatory signals required for tissue formation. Examples ofmeat products that have muscle cells and cartilage cells include chickenbreast or pork ribs.

In a preferred embodiment of the invention, aseptic techniques may beused to culture the muscle cells resulting in meat products that aresubstantially free from harmful microbes such as bacteria, fungi,viruses, prions, protozoa, or any combination of the above. Harmfulmicrobes may include pathogenic type microorganisms such as salmonella,campylobacter, E. coli _(—)0156:H7, etc. In addition, muscle cells grownin culture may be substantially free from parasites such as tapewormsthat infect muscles of whole animals and that are transferred to humansthrough consumption of insufficiently cooked meat. Aseptic techniquesmay also be employed in packaging the meat products as they come off thebiological production line. Such quality assurance may be monitored bystandard assays for microorganisms or chemicals that are already knownin the art. “Substantially free” means that the concentration ofmicrobes or parasites is below a clinically significant level ofcontamination, i.e., below a level wherein ingestion would lead todisease or adverse health conditions.

In another preferred embodiment of the invention, the meat productderived from muscle cells grown ex vivo may be exposed to an electric oroscillating current. Unlike muscle tissues derived from whole animals,muscle tissues grown ex vivo or in vitro may have never been exercised(e.g. never been used to move a leg). Thus, exposing the muscle cells,muscle tissue, or the meat products in vitro to an electric oroscillating current may mimic exercise and increase the similarity intexture between meat grown ex vivo and meat derived from whole animals.The electric or oscillating current may also increase the growth rate ofmuscle cells ex vivo. The electric or oscillating current may be appliedto the muscle stem cells or to the muscle cells after they havedifferentiated from the stem cells.

In another embodiment of the invention, other nutrients such as vitaminsthat are normally lacking in meat products from whole animals may beadded to increase the nutritional value of the meat. This may beachieved either through straight addition of the nutrients to the growthmedium or through genetic engineering techniques. For example, the geneor genes for enzymes responsible for the biosynthesis of a particularvitamin, such as Vitamin D, A, or the different Vitamin B complexes, maybe transfected in the cultured muscle cells to produce the particularvitamin.

In another embodiment of the invention, regulatory factors, growthfactors, or other gene products may also be genetically introduced intothe muscle cells. These factors, known as myogenic regulatory factors(“MRFs”), may stimulate and regulate the growth of muscles in vivo, butmay not normally be produced by muscle cells in vivo or in vitro. Thus,expressing myogenic regulatory factors in cultured muscle cells mayincrease the production of muscle cells in vitro.

In another embodiment of the invention, the meat products derived frommuscle cells in vitro may include different derivatives of meatproducts. These derivatives may be prepared, for example, by groundingor shredding the muscle tissues grown in vitro and mixed withappropriate seasoning to make meatballs, fishballs, hamburger patties,etc. The derivatives may also be prepared from layers of muscle cellscut and spiced into, for example, beef jerky, ham, bologna, salami, etc.Thus, the meat products of the present invention may be used to generateany kind of food product originating from the meat of an animal.

The following examples illustrate how one skilled in the art may makeuse of the current invention to produce meat products in vitro. Methodsin cell biology, cell culture, and immunohistochemistry that are notexplicitly described in this disclosure have already been amply reportedin the scientific literature.

EXAMPLE I

This example illustrates the isolation of pluri-potent mesenchymal stemcells for use in producing meat products in vitro. Mesenchymal stemcells give rise to muscle cells (myocytes), fat cells (adipocytes), bonecells (osteocytes), and cartilage cells (chrondocytes). Mesenchymal stemcells may be dissected and isolated from embryonic tissues of anynon-human animal embryos. In cattle, for example, embryonic mesenchymaltissues that are rich in pluri-potent muscle stem cells are preferablyisolated from embryos at day 30 to 40 or earlier. Once dissected, theembryonic tissues may be minced into small pieces about one millimeterby one millimeter in size in phosphate buffered saline (“PBS”) pH 7.45.Five to ten pieces of the minced tissue may be incubated in 300 μl of0.25% trypsin and 0.1% EDTA in PBS for thirty minutes at 37° C. withgentle agitation. Afterwards, the tissues may be allowed to settle onthe bottom of the tube by gravity or gentle centrifugation. Thesupernatant containing the trypsin/EDTA solution may then be aspiratedand replaced with 300 μl of 0.1% collagenase in PBS for ten to thirtyminutes at 37° C. Colleganese digestion may be repeated for severalcycles as desired. Depending of the viscosity of the solution because ofDNA released from damaged cells, 40 μl of DNase I at 1 mg/ml in PBS maybe added to the collagenase solution in between cycles.

The reaction may be stopped by adding medium such as DMEM or Ham's F-12,or both in 1:1 ratio, (Life Technologies, Rockville, Md.) that issupplemented with 10 mM Hepes, 2 mM L-glutamine (Sigma-Aldrich), 10-20%heat-inactivated fetal calf or bovine serum (Hyclone Laboratories,Logan, Utah), penicillin at 100 units/ml and streptomycin at 100 μg/ml(“complete medium”). Cells may be completely dissociated by gentlypipetting the tissues up and down followed by washing the cells incomplete medium once or twice using a centrifuge. The cells may then beplated onto an appropriate-sized petri dish which may be coated withnatural biomaterials (e.g. collagen, fibronectin, laminin, or otherextracellular matrices) or synthetic biomaterials (e.g. hydroxyapatite,alginate, polyglycolic acid, polylactic acid, or their copolymers), orboth, and may be grown at 37° C. and equilibrated with 5% CO₂.

EXAMPLE II

After mesenchymal stem cells have been isolated, they may be enrichedfor myoblasts or muscle stem cells in culture. Initially, the cells maybe differentially plated on different petri dishes after dissociationand washing as described in Example I. Using a 60 mm petri dish, thecells may first be incubated in complete medium for two to four hours.During this time, epithelial cells will tend to attach quickly to thepetri dish while the myoblasts remain in the supernatant. Thesupernatant may then be collected and the myoblasts may be plated on adifferent petri dish coated with natural or synthetic biomaterials suchas those mentioned in Example I. Myoblasts may be enriched bysupplementing the growth media with growth factors such as skeletalmuscle growth factor, prostaglandin F_(2α) (“PGF_(2α)”), andinsulin-like growth factor I (“IGF-1”).

Further, myoblasts may be differentiated into specific myoctes or musclecells by culturing the myoblasts in complete medium or in minimal media(e.g. complete medium less the fetal calf serum) supplemented withmuscle specific growth or differentiation factors such as PGF_(2α) atconcentrations ranging from 24 pg/ml to 28 pg/ml, and insulin from 10⁻⁶M to 10⁻⁵ M. To more closely mimic in vivo muscle cells, which arenormally innervated by neuronal cells, the culture medium may also besupplemented with appropriate neurotransmitters such as acetylcholine.

EXAMPLE III

Alternatively, myoblasts may be enriched from toti-potent embryonic stemcells. Toti-potent cells may be derived from in vitro fertilized eggs ofan animal using in vitro fertilization techniques, from stem cellspresent in umbilical cords or placenta, or from Embryonic Stem (ES)cells isolated from cells at the blastocyst stage. ES cells, forexample, may be collected, gently dissociated by trypsin, and culturedin vitro with recombinant leukemia inhibitory factor (Chemicon, SanDiego, Calif.) and feeder cells such as growth arrested embryonicfibroblasts cells. These toti-potent cells may be treated with growthfactors such as PGF_(2α) or IGF-1 to induce the cells to differentiateinto myoblasts.

EXAMPLE IV

Using standard immunohistochemistry or in-situ hybridization techniques,myoblasts or myocytes (differentiated muscle cells) may be identified.Briefly, myoblasts or myocytes grown in culture may be transferred intoglass slides coated with appropriate extracellular matrix as describedabove. These cells may be grown to the desired number anddifferentiation using the conditions described above. After a sufficientgrowth and differentiation period, the cells may be fixed with 4%formaldehyde. If intracellular antibody markers or nucleotide probes areto be used, the cell membranes may be permeabilized with 1% NP-40 orTriton-X. Antibodies against markers specific for myoblasts or myocytessuch as myosin, titin, alpha-actinin available from Sigma® may be usedto identify the cells using standard fluorescent immunohistochemistrytechniques. Alternatively, single stranded RNA or DNA probes for thesemarkers may also be used for in-situ hybridization.

In addition, when the muscle cells have been attached to a threedimensional support structure as disclosed below, they may becryo-frozen, sectioned and identified using antibody markers such asantibodies against myosin, titin, 12101, troponin T, alpha actininavailable from Sigma®.

EXAMPLE V

Two or three dimensional scaffolds or supports may be sculpted fromnatural biomaterials (e.g. collagen, fibronectin, laminin, or otherextracellular matrix) or synthetic biomaterials (e.g. hydroxyapatite,alginate, polyglycolic acid, polylactic acid, and their copolymers), orboth. Preferably, the three dimensional scaffolds are sculpted withbranch pathways for nutrients and culture media to reach the internalmass of the forming muscle tissues. Examples of materials andconstruction methods for these scaffolds are provided by U.S. Pat. Nos.5,686,091, entitled “Biodegradable Foams For Cell Transplantation”;5,863,984, entitled “Biostable Porous Material Comprising CompositeBiopolymers”; 5,770,417, entitled “Three-Dimensional Fibrous ScaffoldContaining Attached Cells for Producing Vascularized Tissue in vivo;”and 5,916,265, entitled “Method of Producing a Biological ExtracellularMatrix for Use as a Cell Seeding Scaffold and Implant.” These patentsare hereby incorporated by reference as if fully set forth herein.

The support structure is preferably sculpted to different sizes, shapes,and forms to allow for growth of muscle tissues resembling differenttypes of meat products such as steak, tenderloin, shank, chicken breast,drumstick, lamb chops, fish fillet, lobster tail, etc.

EXAMPLE VI

Adipocytes, chondrocytes, and osteoblasts are all capable ofdifferentiating from pluri-potent mesenchymal stem cells or toti-potentembryonic stem cells. The stem cells may be isolated as described inExample I or III. The stem cells may be cultured in DMEM, or Ham's F-12,or both in a 1:1 ratio. The medium may be supplemented with thyroidhormone, transferrin, insulin, as well as other growth factors, such asinsulin-like growth factor (IGF), basic fibroblast growth factor, andgrowth hormone.

For adipocytes, differentiation may be achieved by treating the stemcells with bone morphogenetic proteins (“BMP”) such as BMP-4 and BMP-2,which are known to induce commitment to the adipocyte lineage. Ahrenset. al., Expression of human bone morphogenetic proteins-2 or -4 inmurine mesenchymal progenitor C3H10T1/2 cells induces differentiationinto distinct mesenchymal cell lineages, DNA Cell Biol., 12:871-880(1993); Wang et. al., Bone Morphogenetic protein-2 causes commitment anddifferentiation in C3H10T1/2 and 3T3 cells, Growth Factors 9:57 (1993).These references are hereby incorporated by reference as if fully setforth herein.

In addition to BMPs, the differentiation of adipocytes may be enhancedwith agonist of peroxisome proliferator-activated receptor gamma (“PPARgamma”) such as BRL 49653 (rosiglitazone). Sottile and Seuwen, Bonemorphogenetic protein-2 stimulates adipogenic differentiation ofmesenchymal precursor cells in synergy with BRL 49653 9 (rosiglitzaone),FEBS Lett, 475(3):201-204 (2000). This reference is hereby incorporatedby reference as if fully set forth herein.

In certain situations, myoblasts may even be induced totrans-differentiate into adipoblasts (adipocyte precursors) by treatingmyoblasts cells or muscle satellite cells with long-chain fatty acids(“LCFA”) or thiazolidinediones, or both. Grimaldi et. al.,Trans-differentiation of myoblasts to adipoblasts: triggering effects offatty acids and thiazolidinediones, Prostaglandins Leukot Essent FattyAcids, 57(1):71-75 (1997); Teboul et. al., Thiazolidinediones and fattyacids convert myogenic cells into adipose-like cells, J. Biol. Chem.270(47):28183-28187 (1995). These references are hereby incorporated byreference as if fully set forth herein.

Thus, meat products with the desired amount of fat content may beproduced by seeding and co-culturing muscle cells and adipocyte cells ata certain ratio. Alternatively, stem cells may be allowed todifferentiate initially into myoblasts and then at a later time, LCFA orthiadolidinediones may be added at different concentrations anddifferent exposure times to trans-differentiate the myoblasts intoadipocytes as desired. Furthermore, the growth of muscle cells and fatcells may be regulated by controlling the concentration of the growthand differentiation factors. For example, if less fat cells are desiredin the final meat product, lesser concentrations of BMP factors may beadded to the culture while a higher concentration of PGF_(2α) and/orinsulin may be added to promote muscle cell growth.

EXAMPLE VII

Chondrocytes or cartilage cells may also be isolated from an animal'sknee or rib cages. Using similar techniques as described in Example I,dissected tissue from the knee or rib cages may be minced, digested withcollagenase, and washed with complete medium. The cells may then bedifferentially plated to increase the purity of chondrocyte cells.

It is known that chondrocytes differentiate in response to mechanicalstress. Thus, preferably, the cells may be subjected to shear flowstress as described in U.S. Pat. No. 5,928,945, entitled “Application ofShear Flow Stress to Chondrocytes or Chondrocyte Stem Cells to ProduceCartilage,” which is hereby incorporated by reference as if fully setforth herein.

Chondrocytes may initially form a first layer of support cells in athree-dimensional scaffold. Myoblasts or adipocyte cells, or both, maythen be seeded onto the chondrocyte layer and grown to the desired size.As such, the chondrocyte layer may provide additional adhesion or growthfactors to the muscle cells.

EXAMPLE VIII

Muscle cells grown in vitro differ from muscle cells grown in vivo inthat in vivo cells are used during exercise or body movements. Asmuscles are used in vivo, muscle cells, in limbs for example, contractand relax in accordance with the movement of the limbs. Hence, to moreclosely mimic the growth of muscle cells in vivo, the cells grown invitro may be exposed to an electric or oscillating current, or pulses ofelectric or oscillating current to contract the muscle cells. Electricprobes may be immersed into the culture media to deliver mild current.Alternatively, the support structure may be coated with electricallyconducting materials. Examples of electrically conducting materials anda method for coating them onto the support structure are described inU.S. Pat. No. 5,843,741, entitled “Method for Altering theDifferentiation of Anchorage Dependent Cells on an ElectricallyConducting Polymer,” which is hereby incorporated by reference as iffully set forth herein.

The preceding examples illustrate the procedures for producing meatproducts ex vivo. They are intended only as examples and are notintended to limit the invention to these examples. It is understood thatmodifying and combining the examples above do not depart from the spiritof the invention.

1. A non-human meat product for consumption comprising non-human musclecells grown ex vivo.
 2. The non-human meat product in claim 1 furthercomprising: a support structure; and wherein the non-human muscle cellsare attached to the support structure.
 3. The non-human meat product inclaim 1 wherein the non-human muscle cells are skeletal muscle cells. 4.The non-human meat product in claim 1 wherein the non-human muscle cellsare derived from animals selected from the group consisting of mammals,birds, fishes, invertebrates, reptiles, and amphibians.
 5. The non-humanmeat product in claim 1 wherein the non-human meat product issubstantially free from harmful microbial contamination.
 6. Thenon-human meat product in claim 1 wherein the non-human muscle cells arederived from pluri-potent or toti-potent cells.
 7. The non-human meatproduct in claim 1 wherein the non-human muscle cells have been exposedto an electric current.
 8. The non-human meat product in claim 1 furthercomprising non-human adipocyte cells grown ex vivo.
 9. The non-humanmeat product in claim 8 wherein the non-human adipocyte cells aretrans-differentiated from non-human myoblasts.
 10. The non-human meatproduct in claim 8 wherein the non-human adipocyte cells are derivedfrom pluri-potent or toti-potent non-human stem cells.
 11. The non-humanmeat product in claim 1 further comprising non-human cartilage cellsgrown ex vivo.
 12. The non-human meat product in claim 10 wherein thenon-human cartilage cells are positioned between a support structure andthe non-human muscle cells.
 13. The non-human meat product in claim 10wherein the non-human cartilage cells have been exposed to mechanicalstress.
 14. A method of producing non-human meat products forconsumption comprising the steps: culturing non-human muscle stem cellsex vivo; seeding the non-human muscle stem cells onto a supportstructure; and growing the non-human muscle stem cells to produce anon-human meat product.
 15. The method in claim 13 wherein the step ofgrowing the non-human muscle stem cells comprises: differentiating thenon-human muscle stem cells into different types of non-human musclecells.
 16. The method in claim 14 further comprising the step: exposingthe non-human muscle cells to an electric or oscillating current. 17.The method in claim 13 further comprising the step: adding nutrients tobe incorporated into the non-human meat products.
 18. The method inclaim 13 wherein the non-human muscle cells are derived from animalsselected from the group consisting of mammmals, birds fishes,invertebrates, reptiles, and amphibians.
 19. The method in claim 13wherein the non-human meat product is substantially free from harmfulmicrobial contamination.
 20. A method of producing non-human meat forconsumption comprising the steps: co-culturing non-human muscle cellsand non-human fat cells ex vivo; seeding the non-human muscle cells andthe non-human fat cells to a support structure; and growing thenon-human muscle cells and the non-human fat cells to produce anon-human meat product.
 21. A method of producing non-human meat forconsumption comprising the steps of: culturing non-human muscle stemcells ex vivo; seeding the non-human muscle stem cells to a supportstructure; treating the non-human muscle stem cells with fatty acids totrans-differentiate the non-human muscle stem cells into adipocytes; andgrowing the adipocytes to produce a non-human meat product.
 22. A methodof producing non-human meat products for consumption comprising thesteps: culturing non-human cartilage cells ex vivo; seeding thenon-human cartilage cells to a support structure; culturing non-humanmuscle cells together with the non-human cartilage cells on or aroundthe support structure; and growing the non-human muscle cells to producea non-human meat product.
 23. The method in claim 20 wherein thenon-human cartilage cells have been exposed to mechanical stress.